Improvement in valves for direct-acting engines



GEORGE F. BLAKE.

Improvement in Steam Engines.

Pate ted Feb. 20,1872.

' a further description.

UNITED STATES PATENT OFFICE.

'GEOBGE F. BLAKE, OF BOSTON, MASSACHUSETTS.

IMPROVEMENT IN VALVES FOR DIRECT-ACTING ENGINES Specification formingpart of Letters Patent No. 123,765, dated February 20, 1872; antedatedFebruary 15, 1872.

I, GEdRGE F. BLAKE, of Boston, county of Suffolk, Commonwealth ofMassachusetts, have invented certain Improvements in Valves forDirect-Actin g Engines, of which the following is a specification:

My invention relates to that class of directacting engines known asautomatic. My improvements consist, first, in a new and improvedarrangement of ports for admitting steam to and exhausting it from theplunger and cushioning the same, and an improved arrangement of thepassages leading to the plunger-cylinder from said ports; second, in thearrangement of a pin for moving the plunger by and with the secondaryvalve at certain times; third, in an improved method ofregulating thespeed of the plunger carrying the main slide-valve.

In the drawing accompanying these specifications, Figure 1 is a sectionshowing the general arrangement of cylinder, valve-chest, valves, andplunger. Fig. 2 shows the arrangement of the secondary slide-valve, withits ports, passages, and cook for regulating the exhaust from theplunger. Fig. 3 shows the end of the valve-rod which operates thesecondary slide-valve. Figs. 4 and 5 are, respectively, face and endviews of the secondary or auxiliary slide-valve, shown over its ports inFig. 2.

General Description.

A is the main cylinder of the engine; B,

the plunger. G isthe main slide-valve, and D the secondary or auxiliaryvalve. The ports a b lead directly to the ends of the plungercylinder,as shown inFig. 2. The ports 0 (1 also lead to the ends of theplunger-cylinder, but enter it a short distance inward from the entranceof ports a b, forming a cushion by the plunger traveling over andclosing the exhaust from the ports 0 d, as will be seen from nicate withthe small secondary exhaust-pipe k, which has attached theregulating-cock m.

The secondary slide-valve face has one cavity, P, and is generally ofthe ordinary D-valve variety. On its back it has projections s s,between which the projections 12 w on the end of the valve-rod fit. Thepin H passes through the body of the plunger, and its end j playsbetween the projections 41 'w on the valve-rod, when the parts aretogether, as

shown in Fig. 1. In operation, thesecondary The ports 9 h commuvalve,acted on by the valve-rod, operated by a tappet-rod or similar means,exposes porta to the steam above the valve, and at the same timeuncoversports 0 and 9 into the cavity 1? in the secondary valve, so as toconnect the same with each other and form a passage from one end of theplunger-cylinder into the exhaust-pipe 7c, and from the steam in thevalvechest to the other end of the plunger-cylinder, and, on reversing,exposes the opposite ports in the same manner, thus operating theplunger. The pin H has sufficient play between the projections 'v w onthe valve-rod, so that if the plunger travels with sufficient rapiditythese projections do not touch the pin;

but if it move slower than the main piston carries the valve-rod, one ofthese projections v 10 catches it and carries it along, and with it theplunger and main slide-valve, thus causing the pump to reverse beforethe main piston San, by any possibility, strike the cylinderhea Thesecondary slide-valve is arranged, as shown, in connection with itsvalve-rod, so as to be readily removed without disturbing the latter.

In slow-running pumps, it is necessary to regulate the movement of theplunger so that the pump may not reverse too suddenly. This I accomplishby means of the cock on on the exhaust-pipe k,- for by closing the samemore or less any desired speed may be given to the plunger, as itcanonly move as fast as the escape of its exhaust will allow it.

I claim as my invention- 1. The plunger B, constructed as described, andoperated, by means of the cock m on the exhaust-pipe k, as set forth.

2. The arrangement of ports a b c d g h with the slide-valve D,constructed and operating substantially as described.

3. The arrangement of projections s s on valve-rod, and projections 12 won valve D, constructed and operating substantially as set forth.

4. The arrangement of the pin H, in combination with the plunger B andsecondary slide.

E. R. STANSBURY.

